We have studied seven women, five premenopausal and two post-menopausal, under this protocol. The data thus far support our hypothesis that estrogen deficiency is associated with an enhanced resorptive response to PTH that is associated with an increased production of IL-6. Specifically, the two estrogen-deficient women showed significatly greater rises in circulating levels of IL-6 and in markers of bone resorption following PTH infusions than did the five premenopausal women. We plan to continue to recruit patients during the next year of the protocol to achieve the number of subjects studied that are consistent with our original estimated for required sample sizes.